Well, chickens can't vomit, as there are no muscles in the Crop. They will drool or food can ooze out only when the crop is full and/or the small outlet to the very small stomach is blocked . Head down lets it flow out. Any oral medicines are wasted, as they are just going into the crop and nothing is absorbed or treated until it reached the stomach, goes through the gizzard and then into the intestines. Choking is a hazzard when the crop is bound. And any treatment to empty the crop manually (through the mouth) runs risk of choking, but can be successful. Surgical emptying of the crop is possible, otherwise, unless if can empty naturally, through the small opening into the stomach, our birds are often doomed. Sad, still hopeful that the crop can empty naturally. It is just a storage place. Good luck.